Mechanistic Insights into the Hydrazine-induced Chemical Reduction Pathway of Graphene Oxide

TL;DR

This study uses density functional theory to elucidate the atomic-level reduction mechanism of graphene oxide by hydrazine and hydroxide ions, clarifying a longstanding scientific question.

Contribution

It introduces a detailed chemical reaction pathway for graphene oxide reduction involving C-H cleavage and dehydroxylation, supported by computational evidence.

Findings

The proposed reduction pathway is thermodynamically feasible.

Hydrazine and hydroxide ions can independently initiate reduction.

Reaction mechanisms differ between basal plane and edge regions.

Abstract

Hydrazine stands out as the most generally used chemical-reducing agent for reducing graphene oxide. Despite numerous experimental and theoretical investigations into the reduction reaction, the reduction mechanism remains unclear. In this study, we propose that, in aqueous hydrazine solutions, both hydrazine and hydroxide ions could initiate the reduction of graphene oxide. We introduce a chemical reaction pathway involving C-H cleavage and a dehydroxylation process for the reduction of graphene oxide. By utilizing density functional theory calculations, the reduction reactions mediated by hydrazine and hydroxide ions are separately investigated. The reaction routes on the basal plane and edge regions of graphene oxide are discussed independently. The density functional theory calculations demonstrate that the proposed mechanism is both thermodynamically and dynamically feasible. This work might contribute to an atomic-level comprehension of a longstanding challenge in the field of graphene oxide.